<?php
/**
 * php获取文件MIME类型
 */

$mime = array (
    //applications
    'ai'    => 'application/postscript',
    'eps'   => 'application/postscript',
    'exe'   => 'application/octet-stream',
    'doc'   => 'application/vnd.ms-word',
    'xls'   => 'application/vnd.ms-excel',
    'ppt'   => 'application/vnd.ms-powerpoint',
    'pps'   => 'application/vnd.ms-powerpoint',
    'pdf'   => 'application/pdf',
    'xml'   => 'application/xml',
    'odt'   => 'application/vnd.oasis.opendocument.text',
    'swf'   => 'application/x-shockwave-flash',
    // archives
    'gz'    => 'application/x-gzip',
    'tgz'   => 'application/x-gzip',
    'bz'    => 'application/x-bzip2',
    'bz2'   => 'application/x-bzip2',
    'tbz'   => 'application/x-bzip2',
    'zip'   => 'application/zip',
    'rar'   => 'application/x-rar',
    'tar'   => 'application/x-tar',
    '7z'    => 'application/x-7z-compressed',
    // texts
    'txt'   => 'text/plain',
    'php'   => 'text/x-php',
    'html'  => 'text/html',
    'htm'   => 'text/html',
    'js'    => 'text/javascript',
    'css'   => 'text/css',
    'rtf'   => 'text/rtf',
    'rtfd'  => 'text/rtfd',
    'py'    => 'text/x-python',
    'java'  => 'text/x-java-source',
    'rb'    => 'text/x-ruby',
    'sh'    => 'text/x-shellscript',
    'pl'    => 'text/x-perl',
    'sql'   => 'text/x-sql',
    // images
    'bmp'   => 'image/x-ms-bmp',
    'jpg'   => 'image/jpeg',
    'jpeg'  => 'image/jpeg',
    'gif'   => 'image/gif',
    'png'   => 'image/png',
    'tif'   => 'image/tiff',
    'tiff'  => 'image/tiff',
    'tga'   => 'image/x-targa',
    'psd'   => 'image/vnd.adobe.photoshop',
    //audio
    'mp3'   => 'audio/mpeg',
    'mid'   => 'audio/midi',
    'ogg'   => 'audio/ogg',
    'mp4a'  => 'audio/mp4',
    'wav'   => 'audio/wav',
    'wma'   => 'audio/x-ms-wma',
    // video
    'avi'   => 'video/x-msvideo',
    'dv'    => 'video/x-dv',
    'mp4'   => 'video/mp4',
    'mpeg'  => 'video/mpeg',
    'mpg'   => 'video/mpeg',
    'mov'   => 'video/quicktime',
    'wm'    => 'video/x-ms-wmv',
    'flv'   => 'video/x-flv',
    'mkv'   => 'video/x-matroska'
);

function _getMimeDetect() {
    if (class_exists('finfo')) {
        return 'finfo';
    } else if (function_exists('mime_content_type')) {
        return 'mime_content_type';
    } else if ( function_exists('exec')) {
        $result = exec('file -ib '.escapeshellarg(__FILE__));
        if ( 0 === strpos($result, 'text/x-php') OR 0 === strpos($result, 'text/x-c++')) {
            return 'linux';
        }
        $result = exec('file -Ib '.escapeshellarg(__FILE__));
        if ( 0 === strpos($result, 'text/x-php') OR 0 === strpos($result, 'text/x-c++')) {
            return 'bsd';
        }
    }
    return 'internal';
}

function _getMimeType($path) {
    global $mime;
    $fmime = _getMimeDetect();
    switch($fmime) {
        case 'finfo':
            $finfo = finfo_open(FILEINFO_MIME);
            if ($finfo)
                $type = @finfo_file($finfo, $path);
            break;
        case 'mime_content_type':
            $type = mime_content_type($path);
            break;
        case 'linux':
            $type = exec('file -ib '.escapeshellarg($path));
            break;
        case 'bsd':
            $type = exec('file -Ib '.escapeshellarg($path));
            break;
        default:
            $pinfo = pathinfo($path);
            $ext = isset($pinfo['extension']) ? strtolower($pinfo['extension']) : '';
            $type = isset($mime[$ext]) ? $mime[$ext] : 'unkown';
            break;
    }
    $type = explode(';', $type);

    //需要加上这段，因为如果使用mime_content_type函数来获取一个不存在的$path时会返回'application/octet-stream'
    if ($fmime != 'internal' AND $type[0] == 'application/octet-stream') {
        $pinfo = pathinfo($path);
        $ext = isset($pinfo['extension']) ? strtolower($pinfo['extension']) : '';
        if (!empty($ext) AND !empty($mime[$ext])) {
            $type[0] = $mime[$ext];
        }
    }

    return $type[0];
}

$path = '1.txt';  //实际上当前路径并不存在1.txt
var_dump(_getMimeType($path));

/*End of php*/